Fuel injection control system for internal combustion engines



April 22, 19.58 R. sElFERT :ITALy 2,831,433

FUEL INJECTION CONTROL SYSTEM FOR INTERNAL cOMEUsTION ENGINES Filed May 7. 1953 2 Sheets-Sheet 1 CHA ED ,55/ FEET Vl/A L TER 5A e7-H.

April 22, 1958 R. sElFERT ETAL 2,831,433

FUEL INJECTIoNcoNTEoL SYSTEM FoE INTERNAL coMBUsToN ENGINES Filed Nay 7. 195s A 2 sheets-sheet 2 Fig.3

"3 E: gz"- :umunumuuluunnuuumlum||||m VVLTER BARTH, y /f/W /LUOR/VX "tinited States Patent O FUEL INJECTION CONTROL SYSTEM FR INTERNAL COMBUSTION ENGINES Richard Seifert and Walter Barth, Friedrichshafen, Germany, assignors, by mesne assignments, to LOrange G. m. b. H., Glatten, Wurttemberg, Germany, a German firm Application May 7, 1953, Serial No. 353,579

Claims priority, application Germany September 16, 1950 2 Claims. (Cl. 11B-41) The invention relates to a system for adjusting and controlling fuel injection devices of internal combustion engines having a plurality of cylinders arranged in a row, particularly for motor vehicles.

The present application is a continuation-impart of our application Ser. No. 246,782, tiled September 15, 1951, which matured into Patent No. 2,717,805 on September 13, 1955.

The fuel injection devices may be of the conventional type in which the injection pump forms a unit with the injection nozzle and which are actuated by means of rockers. The reason why these devices have not been more widely used in spite of their advantages is primarily the fact that their mounting and interchanging is diiiicult particularly because of the adjustment of the individual devices for simultaneous starting of the injection and equal output which is necessary because of manufacturing and mounting tolerances. These adjustments require much time and skill when mounting the devices and can be made only by trained experts. The injection device,

forms a part of the internal combustion engine which part does not only cause diiculties during assembly but also frequently causes uneconomic operation of the engine and other disturbances. These disadvantages are particularly undesired in internal combustion engines for motor vehicles, because the devices can be replaced only in specially equipped workshops and by skilled labor.

-It is an object of the invention to provide a fuel injection system the fuel injection devices of which may be made as spare parts and held in stock and which can be carried along similarly as is done with spark plugs. The new injection devices can be quickly mounted and adjusted by the average operator. Each device can be accurately adjusted by simple means which can be easily manipulated and each device responds correctly to the pulses of a regulator, assuring uniform supply of fuel to the cylinders and uninterrupted economic operation of the engine.

To produce the desired result, the system according to the invention comprises (zz) a fuel injection device which is mounted on the engine as a unit having a fixed basic adjustment of the fuel control element which is connected with the regulator in its basic adjustment; (b) a single revolving regulating shaft for uniform control of the output of a plurality of injection devices, for example for one row of cylinders. This assures absolutely simultaneous and uniform transmission of the regulating movements to the individual injection devices; (c) an adjusting screw on the rocker-arm lever for actuating the pump piston of the fuel injection device for adjusting the inner dead-center position of the pump piston of each device so that all devices start fuel injection at the same moment.

With the system according to the invention, the beginning of the fuel injection can be regulated according to an operating value, for example according to the speed or to the output of the engine, as in conventional injection pumps. According to the invention, the rocker-arms for actuating the pump pistons are eccentrically supported and the eccentrics can be revolved.

In the system according to the invention, the actuating shaft for the inlet valves or the actuating shaft for the exhaust valves is used for actuating the pumps of the injection device. An additional cam shaft is not needed so that the construction is considerably simplified.

ln order to eliminate clearance between the element transmitting the control motions to the pump piston, for example a worm gear wheel sleeve, and a worm on the control shaft and in order to automatically return the regulating element to a position in which the fuel supply is interrupted, the system according to the invention comprises a pull-back spring interposed between the worm wheel sleeve and the pump casing. Advantages in the manufacture of the device and operating accuracy are obtained according to the invention by cutting the worm for actuating the control element into the control shaft.

The novel features which we consider characteristic of our Ainvention are set forth With particularity in the appended claims. The invention itself, however, and additional objects and advantages thereof will best be understood from the following description of an embodiment thereof when read in connection with the accompanying drawing in which- Fig. l shows a longitudinal section through the fuel injection device with the regulating shaft and the actuating elements;

Fig. 2 is a top view of the injection device;

Fig. 3 is a diagrammatic plan View of the system according to the invention.

Like parts are designated by like numerals in all figures of the drawing.

Referring more particularly to Figs. l and 2 of the drawing, numeral 1 designates a one-piece casing whose upper part 2 guides a regulating sleeve 3 supporting a worm gear Wheel sleeve 4. The latter rests on a collar 5 of sleeve 3 and can be fixed against rotation on the sleeve 3 by means of a conical ring 6 which can be pressed against sleeve i by means of a nut 7. Numeral 8 designates a rotatable regulating shaft on which a worm 9 is xed. A pull-back spring 10 having one end connected with the sleeve 3 and the other end co-nnected with the casing 1 prevents clearance between the teeth on sleeve 4 and the worm 9 and assures permanent engagement of elements 4 and 9 for transmitting the regulating movement. Spring 10 tends to rotate the sleeve 3 in a direction in which fuel injection is reduced so that the fuel supply is interrupted when the drive for the regulating mechanism is out of order.

The upper part 2 of casing 1 is provided with openings 12 through which extend protuberances 13 of a sleeve 14. The latter is pushed onto a portion 15 lof square cross-sectional configuration lof a pump plunger 16 and serves for effecting rotation of the pump plunger, affording, at the same time, axial movement of the plunger. The upper end of the plunger 16 abuts against a cap 17 guided in the casing portion 2 and is pressed by a rocker-arm Ztl through a pressure transmitting member 19 against a compression spring 21. The outer end of the rocker-arm 20 carries an adjusting screw 1S for changing the distance between the rocker-arm and the member 19. The lower end of screw 18 has a cap 66 covering the top of member 19.

am (i trolling the amount of fuel and the periods during which the fuel is injected. The groove 30 cooperates with an annular recess 32 and a small groove 33 in sleeve 67; the end face 31 cooperates with the bore 27.

A valve 70 is provided at the end of an aXial bore 25 in the lower part of the plunger 16. The space in the plunger below valve 7G is connected with the outside, i. e. with the space 26 by means of discharge channels 71.

The fuel injection device is held in the cylinder head 36 by means of a bracket 35.

A calibrating disc 40 is provided with a scale 41 (Fig. 2) and can be fixed in the desired position 'by means of screws 43 extending into the upper part 2 of the casing 1. The top of sleeve 3 is provided with a scale 42. A locking ring 44 is inserted between the annular nut 7 and the compression ring 6.

Fig. 3 illustrates an arrangement of the injection devices and a mechanism for regulating the devices. Numerals 45 and 46 designate two cylinder heads which are arranged in a row. The inlet valves are designated by numerals 47 and the exhaust valves by numeral 48. Numeral 49 designates the control shaft for the rockerarms 76 actuating the inlet valves. The rocker-arms are mounted on a shaft 75 revolvable in bearings 72 and in intermediate walls 73. Numeral 50 designates the control shaft for the exhaust valves. Shaft 50 is used for actuating the pumps of the injection devices 51 and 52. The rocker-arms 20 swing on a shaft S4 and are actuated by cams 55 and 56.

The revolvable regulating shaft 8 is provided with worms 59, 60 for transmitting the regulating motions to the injection devices. The shaft 8 is actuated by a yspeed regulator 61 through a linkage 62. The shaft 69 of the regulator is driven by the exhaust control shaft 50 with which it is connected by a shaft 66 and spur gear wheels 67 and 74.

ln the illustrated injection device the injected amount of fuel is determined in the conventional manner by the duration of the closure of the pressure chamber 26, i. e. by the time during which the discharge ports 27 and 28 do not communicate with the pressure chamber. The injection begins when the edge of the face 31 of the pump plunger moves past the lower edge of the bore 27. The injection ends when the pressure chamber 26 communicates through the groove 33, the control groove 30, the annular groove 32, and the bores 28 and 29 with the return conduit 23. The positions of the control edge of the plunger face 31 and of the control groove 30 relatively to the return ports is de-cisive for the beginning and ending of the injection and must be the same in all injection devices after they have been mounted on the engine. Valve 70 closes after a determined pressure has been built up in space 26 by a down stroke of piston 16, so that no fuel can escape through the valve 70 during the injection period. Valve 7@ opens upon the upstroke of the pump plunger and permits flow of fuel from the bore 2S and through ports 71 into the pressure chamber 26, which remains filled also upon the upstroke of plunger 16.

After assembly, the injection devices are calibrated on the test bed for a determined amount of fuel to be injected, the basic adjustment being indicated by the relative positions of the regulating sleeve 3 and the upper part 2 of the pump casing 1. In the illustrated embodiment of the invention markings 41 and 42 on the annular cali- 'brating or scale element 40 (or casing 1) and on the sleeve 3, respectively, are used for determining the position of the revolvable sleeve 3 and consequently of the fuel admission control element (control groove 30 on plunger 16) relatively to the stationary casing. At first the regulating sleeve 3 provided with the markings 42 is revolved until the control groove 3? stops injection at a predetermined moment, the beginning of the injection being fixed, to determine the amount of fuel injected. When the sleeve 3 is in the desired position, the position -causing lifting of the face 31.

of .element 40 is adjusted to align the marking 41 thereon with the marking 42 whereupon the cover is fixed on casing part 2 by means of the screws 43. The regulating sleeve 3 can now be left alone until the device is mounted on the internal combustion engine, the spring 10 turning the sleeve 3 into abutting position which is determined by the width of the opening 12. If in this position the protuberances or pins 13 abut against the lateral Walls of openings 12, the pump plunger does not deliver any fuel so that no damage is done in case of operating irregularities.

T he adjusted devices can be put in storage and shipped Without changing the initial adjustment. The devices can be readjusted after mounting on the internal combustion engine 'by revolving the sleeve 3 until the relative position of its marking 42 and of the marking 41 on the cover 4t) corresponds to the basic adjustment. After meshing the teeth of parts 4 and 9, the freely rotatable sleeve 4 is made fast on sleeve 3 by tightening the nut 7 and thereby the ring 6. The pull-back spring 10 climinates play between the Worm 9 and the worm wheel sleeve 4.

The guide cap 17 includes an abutment abutting against a corresponding abutment formed on the Calibrating or scale element 4G prior to mounting of the device on the internal combustion engine so that the measure y (Fig. l) is zero. The measure y, which is found on the test-bed, determines the basic position of the face 31 for a determined beginning of the injection. The measure y is restored by adjustment 0f screw 18 and is exactly measured after placement of the rocker-arm 20 on the member 19 and after abutment of the cam follower roller 11 against the base circle of the cam 5S has been effected. Since the measure y has been previously determined, all devices can be adjusted in the aforedescribed manner after they have been installed for simultaneously initiating fuel injection.

Beginning of the injection can be changed by changing the distance y and by consequently changing the position of the face 31. This change can be effected, for example, by providing an eccentric bearing 65 for the rocker-arm 20 on the shaft 54 (Fig. 3). The fulcrum of the rocker-arm is lifted when the eccentric is revolved, This delays beginning of the injection. Revolving the eccentric in the opposite direction advances beginning of the injection. l

As shown in Fig. 3, the rocker-arm shaft 54 can be revolved by the regulator 61 through spur gear wheels 63 and 64, according to an operating value of the internal combustion engine, for example its speed. In this case the beginning of the injection is advanced upon an increase of the speed of the engine and is retarded when the speed of the engine decreases. Regulation of the end of the injection period, i. e. revolving of the pump plunger 16 and of the control groove 30, is eifected, as has been described, by means of the regulating shaft 8, the Worm 9, and the regulating sleeve 3, in accordance with pulses produced by the regulator 61.

The aforedescribed injection device can'be easily mounted and dismounted without impairing accuracy of time and amount of fuel injection.

While we have shown and described a specific embodiment of our invention, it will he apparent to those skilled in the art that various changes, modifications, substitutions, additions and omissions may be made therein without departing from the spirit and scope of our invention as set forth in the appended claims.

What we claim as our invention is:

i. A rocker arm actuated fuel pump for an internal combustion engine in which the start and the amount of fuel injection can be adjusted prior to mounting the pump on the engine, comprising a casing, a pump plunger movable in said casing, the latter having an opening for insertion and removal of the pump plunger, connecting means for connecting the rocker arm with said plunger, said connecting means extending through said opening and including a member adjustably connected with the rocker arm for adjusting the length of said connecting means and the position of the range in which said plunger reciprocates in said casing, an abutment connected with said plunger, a Calibrating element mounted on said casing and forming an abutment adapted to abut against the abutment connected with said plunger forV determining a basic axial position of said plunger in said casing, said casing having inlet and outlet ports for nthe fuel oil, said plunger being rotatable in said casing and having conduits communicating with said ports, the flow area between said conduits and said ports depending on the angular position of said plunger in said casing, said casing having a cylindrical portion coaxial of said plunger, means for rotating and changing the angular position of said plunger in said casing, said last-mentioned means comprising a iirst sleeve rotatable on the cylindrical portion of said casing, a second sleeve surrounding said rst sleeve, and means connected with said sleeves for interconnecting said sleeves in a predetermined relative position, said Calibrating element mounted on said casing being rotatable on the longitudinal axis of said sleeves and having a portion provided with a scale adjacent said rst sleeve, the latter having a mark cooperating with said scale for indicating a basic position of said first sleeve.

2. A fuel pump according to claim 1 comprising a spring having one end connected with one of said sleeves, the other end of said spring being connected with said casing, said spring tending to rotate said sleeves in a predetermined direction on said casing.

References Cited in the file of this patent UNITED STATES PATENTS 1,444,778 Chadwick Feb. 13, 1923 2,040,847 Hesselman May 19, 1936 2,106,932 Rosen Feb. 1, 19.38 2,315,907 Starr Apr. 6, 1943 2,410,947 Johnson Nov. 12, 1946 2,521,919 Johnson Sept. 12, 1950 2,540,755 Nystrom Feb. 6, 1951 2,717,805 Seifert et al. Sept. 13, 1955 FOREIGN PATENTS 825,628 France Mar. 9, 1938 870,594 France Mar. 16, 1942 

